Okay so imagine Spock Prime in the days after Nero destroyed Vulcan.
After all of the chaos settles and people start to mourn and plan how to move forward, Spock Prime is (illogically) blaming himself for the destruction of his planet and the billions of lives that were lost. Deep down, he knows that the blame rests with Nero, but he is also acutely aware that his actions played a role- starting with the Kelvin. He is partially responsible for this version of his friend/brother/t'hy'la growing up without a father. So, he starts looking into this reality’s Jim Kirk, because there will never be a universe where he does not care about him. He is devastated to find out that he still was on Tarsus. He had held out hope that by one horrible tragedy happening, another could have been avoided. After all, the death of his father would have been more akin to a tidal wave than the flapping of a butterfly’s wing. He digs farther and farther, finding new information and grieving for the young man that will shape his counterpart’s life (that had shaped his life). A police report about a boy driving a car off of a cliff, an (unresolved) notice of George Kirk Jr.’s disappearance, Starfleet logs about the aftermath of Tarsus, and then… nothing, nothing for years until suddenly there are outstanding aptitude scores with a rap sheet to match. Then, the official Starfleet cadet headshot, and glowing remarks from professors (with demerits and discipline records to match).
When he reaches the end, he feels as though he had lost his world again. He mourns for the young boy who would never be the same man he knew (he thinks my fault, my fault, my fault), and it sinks in that, for the first time in his life, he is truly and completely alone in this universe.